Blood concentrations of folate have risen in the US and Canada following mandatory folate fortification. Fewer women of childbearing years have low folate blood concentrations, but there still are a small number of women of childbearing age who have low blood folate levels

The incidence of children being born with NTDs has been reduced following mandatory folic acid grain fortification in the US and Canada. In the US, a reduction of 23% to 54% in spina bifida (SB) and a reduction of 11% to 16% in anencephaly (AN) have been reported. In Canada, a 53% reduction in SB and a 31% reduction in AN has been reported.

There was limited evidence for the following:

There was limited evidence that stroke mortality has declined in US and Canadian populations following mandatory folate fortification

There was limited evidence that the incidence of colorectal cancer has increased in the US and Canada following mandatory folate fortification.

[Provisional: Finally, there was clear and consistent evidence that supplementation with additional folic acid does not reduce CVD risk. There was inconsistent evidence that supplementation with additional folic acid reduce risk of stroke.]

Systematic Review Questions: (Click or hover over links below for more information.)

Strong evidence demonstrates that folic acid supplementation with or without additional B vitamins in adult men and women with pre-existing vascular disease, does not appear to reduce risk of cardiovascular disease, and may increase risk slightly.